Partial hepatectomy and liver regeneration in pigs--the response to different resection sizes.

Liver regeneration has been extensively studied in the rat and dog models but pigs have seldom been used. They resemble man closely in their omnivorous diet and their gastroenterological and endocrinological responses. This paper describes techniques of 15, 50, 65, and 70% partial hepatectomy in the pig. Thymidine kinase activity and mitotic index were used as indices of liver regeneration. The timing and events of the regenerative response in the pig compared favorably with other animal models and the maximum regenerative response occurred on the third postoperative day, irrespective of the size of the partial hepatectomy. The 15% partial hepatectomy, which shows a minimal response to resection, provides a suitable "primed" model for the study of stimulatory substances.